Add initial prototype for the GN meta-buildsystem.

tools/gn/functions.h

Index: tools/gn/functions.h
diff --git a/tools/gn/functions.h b/tools/gn/functions.h
new file mode 100644
index 0000000000000000000000000000000000000000..806de1dda990ade27d2ee057a43a350c154cfbce
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+++ b/tools/gn/functions.h
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+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef TOOLS_GN_FUNCTIONS_H_
+#define TOOLS_GN_FUNCTIONS_H_
+
+#include <string>
+#include <vector>
+
+class Err;
+class BlockNode;
+class FunctionCallNode;
+class Label;
+class ListNode;
+class ParseNode;
+class Scope;
+class SourceDir;
+class Token;
+class Value;
+
+Value ExecuteFunction(Scope* scope,
+                      const FunctionCallNode* function,
+                      const std::vector<Value>& args,
+                      BlockNode* block,  // Optional.
+                      Err* err);
+
+// Function executing functions -----------------------------------------------
+
+Value ExecuteTemplate(Scope* scope,
+                      const FunctionCallNode* function,
+                      const std::vector<Value>& args,
+                      BlockNode* block,
+                      Err* err);
+Value ExecuteExecScript(Scope* scope,
+                        const FunctionCallNode* function,
+                        const std::vector<Value>& args,
+                        Err* err);
+Value ExecuteProcessFileTemplate(Scope* scope,
+                                 const FunctionCallNode* function,
+                                 const std::vector<Value>& args,
+                                 Err* err);
+Value ExecuteReadFile(Scope* scope,
+                      const FunctionCallNode* function,
+                      const std::vector<Value>& args,
+                      Err* err);
+Value ExecuteSetDefaultToolchain(Scope* scope,
+                                 const FunctionCallNode* function,
+                                 const std::vector<Value>& args,
+                                 Err* err);
+Value ExecuteTool(Scope* scope,
+                  const FunctionCallNode* function,
+                  const std::vector<Value>& args,
+                  BlockNode* block,
+                  Err* err);
+Value ExecuteToolchain(Scope* scope,
+                       const FunctionCallNode* function,
+                       const std::vector<Value>& args,
+                       BlockNode* block,
+                       Err* err);
+Value ExecuteWriteFile(Scope* scope,
+                       const FunctionCallNode* function,
+                       const std::vector<Value>& args,
+                       Err* err);
+
+// Target-generating functions.
+Value ExecuteComponent(Scope* scope,
+                       const FunctionCallNode* function,
+                       const std::vector<Value>& args,
+                       BlockNode* block,
+                       Err* err);
+Value ExecuteCopy(Scope* scope,
+                  const FunctionCallNode* function,
+                  const std::vector<Value>& args,
+                  Err* err);
+Value ExecuteCustom(Scope* scope,
+                    const FunctionCallNode* function,
+                    const std::vector<Value>& args,
+                    BlockNode* block,
+                    Err* err);
+Value ExecuteExecutable(Scope* scope,
+                        const FunctionCallNode* function,
+                        const std::vector<Value>& args,
+                        BlockNode* block,
+                        Err* err);
+Value ExecuteSharedLibrary(Scope* scope,
+                           const FunctionCallNode* function,
+                           const std::vector<Value>& args,
+                           BlockNode* block,
+                           Err* err);
+Value ExecuteStaticLibrary(Scope* scope,
+                           const FunctionCallNode* function,
+                           const std::vector<Value>& args,
+                           BlockNode* block,
+                           Err* err);
+Value ExecuteGroup(Scope* scope,
+                   const FunctionCallNode* function,
+                   const std::vector<Value>& args,
+                   BlockNode* block,
+                   Err* err);
+
+// Helper functions -----------------------------------------------------------
+
+// Verifies that the current scope is not processing an import. If it is, it
+// will set the error, blame the given parse node for it, and return false.
+bool EnsureNotProcessingImport(const ParseNode* node,
+                               const Scope* scope,
+                               Err* err);
+
+// Like EnsureNotProcessingImport but checks for running the build config.
+bool EnsureNotProcessingBuildConfig(const ParseNode* node,
+                                    const Scope* scope,
+                                    Err* err);
+
+// Sets up the |block_scope| for executing a target (or something like it).
+// The |scope| is the containing scope. It should have been already set as the
+// parent for the |block_scope| when the |block_scope| was created.
+//
+// This will set up the target defaults and set the |target_name| variable in
+// the block scope to the current target name, which is assumed to be the first
+// argument to the function.
+//
+// On success, returns true. On failure, sets the error and returns false.
+bool FillTargetBlockScope(const Scope* scope,
+                          const FunctionCallNode* function,
+                          const char* target_type,
+                          const BlockNode* block,
+                          const std::vector<Value>& args,
+                          Scope* block_scope,
+                          Err* err);
+
+// Validates that the given function call has one string argument. This is
+// the most common function signature, so it saves space to have this helper.
+// Returns false and sets the error on failure.
+bool EnsureSingleStringArg(const FunctionCallNode* function,
+                           const std::vector<Value>& args,
+                           Err* err);
+
+// Returns the source directory for the file comtaining the given function
+// invocation.
+const SourceDir& SourceDirForFunctionCall(const FunctionCallNode* function);
+
+// Returns the name of the toolchain for the given scope.
+const Label& ToolchainLabelForScope(const Scope* scope);
+
+// Generates a label for the given scope, using the current directory and
+// toolchain, and the given name.
+Label MakeLabelForScope(const Scope* scope,
+                        const FunctionCallNode* function,
+                        const std::string& name);
+
+// Function name constants ----------------------------------------------------
+
+namespace functions {
+
+extern const char kAssert[];
+extern const char kComponent[];
+extern const char kConfig[];
+extern const char kCopy[];
+extern const char kCustom[];
+extern const char kDeclareArgs[];
+extern const char kExecScript[];
+extern const char kExecutable[];
+extern const char kGroup[];
+extern const char kImport[];
+extern const char kPrint[];
+extern const char kProcessFileTemplate[];
+extern const char kReadFile[];
+extern const char kSetDefaults[];
+extern const char kSetDefaultToolchain[];
+extern const char kSetSourcesAssignmentFilter[];
+extern const char kSharedLibrary[];
+extern const char kStaticLibrary[];
+extern const char kTemplate[];
+extern const char kTest[];
+extern const char kTool[];
+extern const char kToolchain[];
+extern const char kWriteFile[];
+
+}  // namespace functions
+
+#endif  // TOOLS_GN_FUNCTIONS_H_